The present invention relates to a ball and socket joint having improved load-carrying capacity, extended range of motion and simplicity of structure, as compared to conventional ball and socket joints.
Ball and socket joints are commonly used in motor vehicle steering tie rod assemblies, in drag links, torque rods and like structures, in which there is a requirement for transmitting a force from one member to another while permitting one member to swivel or pivot relative to the other.
Ball and socket joints generally consist of a stud terminating in a ball member disposed in swivelling slidable engagement within a socket member having a concave spherical segment conforming to that of the ball. The engaged bearing surfaces of the ball and socket are often biased towards each other such as to provide a relatively tight assembly eliminating play and rattle and automatically compensating for wear of the bearing surfaces.
The shortcomings of conventional ball and socket joints are many. The load-carrying capability of the joints is limited to the relatively small area of the peripheral surface of the ball engaged with the corresponding surface of the socket. A complex structure is required for providing pre-load of the bearing surfaces in arrangements where it is desired to prevent rattles and play and to ensure automatic break-in and usage wear compensation. The range of motion, or amount of angulation, between the elements interconnected by the joint and the load-carrying characteristics of the assembly are limited.
The invention disclosed in copending application Ser. No. 061,644 remedies the inconveniences and shortcomings of the prior art by providing a knuckle or swivel joint structure comprising a stud member terminating in an integral hollow half-ball head member whose peripheral spherical surface engages a conforming concave spherical surface of the socket member, the half-ball member having a substantially hemispherical convex retainer bearing member holding the half-ball peripheral surface in swivelling sliding engagement with the socket spherical bearing surface. Pre-load of the bearing surfaces in engagement is effected by elastically prestressing the retainer bearing member or by means of a resilient ring member urging the retainer bearing member towards the hemispherical cavity in the half-ball member of, alternatively, urging a segment of the socket spherical surface in engagement with the half-ball spherical peripheral surface.